Interlocking machine for railroads



Feb. 23, 1932. w. K. HOWE INTERLOCKING MACHINE FOR 'RAILROADS 3 Sheets-Sheet Filed Aug. 26 1929 Nw mm NEE 5 E INVENT BY w. 7:.

MM MTTORNEY Feb. 23, 1932. w. K. HOWE 1,846,724

INTERLOCKING MACHINE FOR RAILROADS Filed Aug. 26, 192.9 s Sheets-Sheet 2 FIG.2.

Flca. 2A.

TTORNEY Feb. 23, 1932. w. K. HOWE INTERLOCKING MACHINE FOR RAILROADS FIG.6.

PIC-31.7.

FIG. 8. Q. I

INVENTOR 55 BY 52 WW ATTORNEY V Patented Feb. 23, 1932 UNEEEE) stares rarest OFFICE,

wmrnnor K. nown, or noorrnsmnn, NEW YORK, ASSIGNOR roenminnl. nArLwaY srenar. coMrAnY, or ROCHESTER, new YORK I mrnnnocxme MACHINE non narrnonns Application} filed August as, 1929. Serial No. 388,437.

J This invention relates to interlocking machines, and more particularly pertains to indication latch mechanisms used therein.

Inonetype of interlocking system, it has ,beenproposed that the control levers shall have two extremevor full posit-ions, that'is, a tuli normal position and a full reverse position with each of thesefull positions preceded by their corresponding intermediate steps which are conveniently termed indicating positions, by'reason of the. indication of the fact that the trathc controlling function has completed its operation which is required before the control-lever is allowed to be 5 moved to a corresponding full position.

Such indication positions serve the purpose of maintaining the mechanical interlocking between levers ina locked condition until the indicationof the completed operation ofthe 2o trai'hc controlling function is received.

. In this type of interlocking system, the

lockin means for reventin :the control a 7 P c lever from bein movedout of an ndicatm I I I b I u n posltion to its correspondmg full pos tion, 1s

5 commonly known as an indication latch mechanism, which isreleasedby the energization of a suitable electromagnet associated therewith.

Heretofore, it has been; necessary in the 1 control of the switchnaachines at the two ends of a cross over, in order to make it posslble for the operator to control both switch machines with one operation, to provide duplicate control levers with one lever rigidly connected to the other; Although such an arrangement eliminates the number ofcontrol operations for the operator,.it does not reduce the size oftheinterlocking machine, because two lever spaces arerequ'iried to provide the necessary two indication latch mechanisms. q M

With the above considerations in mind, it is proposed, according to the present invention, to provide atype of indication latch mechanismadaptable for multiple combinations,,so that more thanone traffic controlling tunc'tionmay be operated from the circuit controllers offone control lever withseparate indication latch mechanisms, corresponding to eachtrai'fic'controllin function 'overnin the movement for that particular control lever. V

. A further object is to provide a compact and sturdy mechanism so organizedthatthe locking means preventing the movement of the control lever at certain times are slid-. ably connected to the frame members, thus eliminatingthe major stresses from th? Pivoted members of the mechanism.

it is also an ob '.ect of this invention to pro; vide such an indication latch mechanism in a unit structure which may be easily disengaged from its control. lever for removing itfrom the interlocking machine without dis; turbing other indication latch mechanisms, .or any other devices.

Various other objects, purposes and characteristic features will bein part pointed'out and in part obvious as a description of the in,- vention progresses.

In describing the invention in detail, reference will .be made to the accompanying drawings in which like reference characters refer to like objects, and iniwhich 1 1 Fig. l is a side elevation of a single indication latch mechanism constructed according to the present invention and mounted upon the frame of an interlocking machine in coacting relation with an interlocking control-lever;

Fig. 2 is a side elevatlon of a single indi- "reverse indicating. position with certain parts removed Fig. :3 isa cross section of a single indication latch mechanism takenon line 33 of F s- 2; v

Fig. 4 is a cross section of a single indication latch mechanism taken'on line of Fig. 5 is across section of a single indication latch mechanis1ntaken. on .line 5..5 of Fig.2; d a '7 Fig- 6isside leva o of a m tiple or double indication unit latch mechanism constructed according to the present invention with certain parts removed;

Fig. 7 is a cross section of a multiple indication latch mechanism taken on line 7-7 of Fig. 6;

Fig. 8 is a cross section of a multiple indication latch mechanism taken on line 88 of Fig. 6;

Fig. 9 is a cross section of a multiple indication latch mechanism taken on line 9-9 of Fig. 6;

Fig. 10 is a top view of a spring biased wedge supporting means;

Fig. 11 is an end View of the spring biased wedge supporting means of Fig. 10.

Fig. 12 is a side view of spring biased wedge supporting means of Fig. 10.

A single indication latch mechanism is one which is associated with a control lever that operates a single trafiic controlling function, while a double indication latch mechanism is one associated with a control lever operating two traffic controlling functions. It is of course understood, in the case of the double indication latch mechanism, that both of the indication magnets must be energized thus releasing each locking neans before the movement of the lever is allowed. As the double indication latch mechanism is a modification of the single indication latch mechanism, the latter will be described in detail with the modifications of the multiple unit pointed out as the description of the present invention progresses.

With reference to the drawings, Fig. 1 shows a single indication latch mechanism IL mounted within an interlocking machine in a coacting position relative to a lever IJ, in a manner such for example as set forth in my pending application Ser. No. 380,418 filed July 23, 1929 and entitled Interlocking machines. However, in order to show the relation between the various parts of an in dication latch mechanism IL, and the interlocking lever L with which it is associated, it is pointed out that the indication latch mechanism IL is mounted upon an interlocking frame bed member 5 at the left hand end and is held in position by a spring biased wedge supporting means or detent D at the right hand end. The lever L is provided with a slot 6 which receives a projection 9 integral with an actuating cam member 9 included within the indication latch mechanism IL.

The indication latch mechanism includes two frame members 7 and 8 (see Fig. 3) which are of irregular shape so as to provide the necessary recesses, pivot points, bushings and guides for various operating members. In Fig. 1, the frame member 7 has not been shown in position, so that the various moving parts are shown as mounted upon the frame member 8.

Along the top portion of the frame member 8 a guiding slot 8 (see Fig. 5) is provided for an actuating cam member 9, having a projection 9 which suitably fits into the slot 6 of control lever L as heretofore stated. Also, along the lower portion of the frame member 8 another slot 8 is provided for a detaining cam member 10 which is rigidly attached to the cam member 9 by a plate 11. This plate 11 is permanently riveted to the cam members 9 and 19 by rivets 12. Thus, any motion transmitted from the lever L to the projection 9 thereby causes the cam members 9 and 10 to move in a reciprocating manner in respect to the frame members 7 and 8.

Between the slots 8 and 8" provided for the cam members 9 and 10, there are projections 13, 14, 15, 16, 17, 18 and 19 which are an integral part of frame member 8, and serve to inclose and form guides for certain movable parts. The projections 14, 15, 16 and 17 form part of a guiding slot 8 (see Figs. 2 and t) which is perpendicular to the slots 8 and 8 and furnish a guide for a movable de tent 20 which may move in a reciprocating manner in respect to the frame member 8. This movable detent 20 is of suflicient thickness to allow a latch 21 (see Fig. 4:) to pass through a slot 20. Thus, with the latch 21 pivoted upon a pin 22 which is secured to the frame member 8 and passes into a suitable bushing of frame member 7, the movable detent 20 may be operated in a vertical direction in a manner that the latch 21 will turn upon the pin 22.

A latching pawl 23 is pivoted upon a pin 241- which is secured to the frame member 8 and passes into a suitable bushing in the frame member 7. This latching pawl 23 is biased to an extreme position bya coil spring 25 being mounted upon a pin 26, which pin is secured to the projection 18.

The projections 18 and 19 form a part of a vertical guiding slot for a safety dog 27. This safety dog 27 is provided with a suitable recess for a coil spring 30, thus supplying means to bias a steel ball 31 against a plate 32, which plate 32 is secured to the safety dog 27 by screws 33. The plate 32 contains a counter sunk opening to permit a part of the steel ball 31 to sufliciently pass through to engage a slight depression in the frame member 8 for a purpose to be hereinafter explained.

The latch 21, the latching pawl 23 and the safety dog 27 are held into position against the frame member 8 within their slots by a plate 3d which fits within suitable recess within the projections 13, 1 1, 15, 16, 17, 18 and 19 and is secured into position by screws 35 which thread into the projections 13 and 19. lVith the latch 21 thus held into position the movable detent 20 is also provided with retaining means.

A link 10 is provided with a pin 41 which frame member 7 holdsthe cam members 9 and "10 insa guiding-slot 7 in as much as the frame member '7 "issecured-to the frame member 8 by bolts 48 and49, these bolts beingv provided with suitable lock washers. Spacer members b t tnareprovided for the bolts/l8 in as much :as the frame-members 7 and Sido not come into contactwith each other at these'points' 'YVith reference to Figs; 3 and l, it is noted that'the pins 22 and 24 extend from theframe .member 8 throughthe frame member 7, thus making. necessary the slots 11 and 11 in the plate 11,- (see Fig. 1), so that the lever L may move the cam members Sand 10in a reciprocating manner. Thus, the pins 22 and 2 tfurnishllimits-lf or themovement of the cam members 9. and 10. Also, a' slot 11 is provided to prevent the interference of the screw with the movement of the plate 11.

IThe actuating cam member 9 is provided wlth a PIOjeCtlOIl hav ng the cam surfaces 9* .Land 9.whi-ch come into engagement with the cam surfaces .20 and 20 of the detent. 20 --at-;certain timesfto force the detent 2() into a .slotor depression in the detaining cam 1118111- berf.10.fl This slot or. depression within the cam member 1015 provided with cam surfaces IQa-ndilO which at certain times engage the cam surfaces :20. and :20? of the: detent ".20.

The actuating .camanember 9. also has .an-

other. projection having cam surfaces '9 ziLlld 9 whic-hengage at certain times'the .projection 23 of the latching .pawl 28 and simul taneously therewith the projection 27 of'the safety :dog27. 'The actuationlof this safety dog .27 in a downward direction (see Fig. 2) forces ltulnilO a slot or depresslon provided "in the detaining cam member 10. This slot in the detaining cam memberis provided with limits 10 and 10 which come into. contact a with the safety dog 271 at. the-same time that the cam surfaces IO HIan d 10 'come into contactwith the movable detent 20., withthe eX- ception :of course of thosetimes that the -'safety dog is-actuated to anwupper position for releasing the lever. L.

The detaining cam member 19.:a1so has a projectronvhavmg. verticalv surfaces "10 and Thus, it is seen that thezactuating cam memher 9 has camsurfaces Ewh-iclractuate or operate-the :detent .20.; Lth-e pawl .23, and the safety "accomplished. .int'his position biasing the spring 25. by the J dog- '27 Ito their. actively r detaining positions, while :the detaining cam member 10, has cam surfaced and; limiting projections which activelywengage thedetent 20, the safety .dog

27 .and the :link 40 to detain: or prevent the movement of. the. lever L at certain :times as hereinafter explained; .lVhen thelever L is operated toward the left (see Fig, :1),.it canonly beoperated as far as thexreversez indication position i which causes the parts to assume positions asshown in Fig. 2A during which movement the cam member .9 moves toward the. left-(sce Fig, 2) until i the. cam surface 9 comes .into contact with the cam surface 20 of the ,detent 2O to force the movable detent 120. toa -lower extreme. or active position within the cam member 10. As soon as the movable detent 20'assumes a lower. position, so that the latch 21 mm a po-sitiomasshown in Fig. "2A, the cam surface 9 comes-into contact withthe right: hand cam surface of projection 23 and the right hand cam surface of, projection 27?, which forces the latching pawl.23.,t o engage orlockthe latch .21. Also, thesafety dog v is. caused to -assume a position, as shown in Fig. 2A, so that after the latching pawl .23 is in alockingposition, the lever L is pre ventedffrom further movement by the cam surface 10? coming into contact with the cam surface 20 of the locked movable detent 120,. and the limiting projection 10" coming into contact with said safety dog 27.

The energization of the indication: magnet .IM which is accomplished by the completion of the. movement of. the trafiic controlling device, operated bythe lever L, pulls the armature 43in an upwarddirection which motion is transmitted through the plunger 42' through the sliding link 40 to the safety dog .27. With the safety dog 27actuated to .an upper extreme or inactive position, the

latchingpawl 23 is caused torelease the latch 21, so that the detent 20 no longer actively engages theidetaining cam memberlO but is also forced to-an inactive position by further movement of-the lever L toward the left orfu'll reverse positionwhich mayv now be The latching p'awl23 is held engagementof the steel ball 31 into the depression' provided for it in the frame member 8. as shownin Fig. 3.

.jecting surface 10 of the detainingcammem- .her 10 which engages the movable link 404 10 which-engage the limit: l0 whenever said clink 4'O. ism-ctuated to an:up 3erposition.

. The operation of the lever'L .to the normal the left hand cam surface of the projection 23 and the left hand cam surface of the projection 27 a to cause the latching pawl 23 to lock the detent 20 and the safety dog 27 to engage the limit 10. The lever L is thus locked in the normal indicating position as explained for the reverse indicating position with further movement toward the full normal position being prevented by the cam surface 10 engaging the cam surface 20 of the movable detent 20, and the engaging of the limiting surface 1O with the safety dog 27. The energization of the indication magnet TM in a similar manner releases the locking of the movable detent 20 and disengages the safety dog 27 from the limiting surface 10, so that the full normal position of the lever L may be attained.

It will be noted, that the movement of the lever L from one indicating position to the other indicating position is always possible except when the indication magnet TM is energized at which time the limiting surfaces 10 and 10 engage the slidable link 40, with the lever L in the reverse indicating position or in the normal indicating position respectively.

With reference to Figs. 6, 7, 8 and 9, one modification of the present invention is shown providing a double indication latch mechanism, that is, a mechanism requiring an indication from each of two traffic controlling functions before the control lever which it governs may be moved to a full position.

This double indication latch mechanism IL is the same size unit as the single indication latch mechanism and may be mounted in a coacting position relative to the lever L of Fig. 1 in a similar manner to the single indication latch mechanism as shown. In place of the indication magnet IM, there are two such magnets 1M and 1M provided, which have armatures 50 and 51 respectively. These armatures 50 and 51 operate plungers 52 and 53 respectively being so positioned on each side of the center line of the magnets as to operate their respective links 54 and 55, which links release their respective locking mechanisms in the same manner as the link to of the single indication latch mechanism.

The double indication latch mechanism is provided with a two part frame having right and left hand frame members 56 and 57 both of which are similar to the frame member 8 as may be seen by the comparison of Fig. 9 with Fig. 5.

The frame member 56 provides guiding slots for the actuating cam member 58 and the detaining cam member 59, while the frame member 57 provides guiding slots for the actuating cammember 60 and the detaining cam member 61. The actuating cam member 58 and the detaining cam member 59 are rigidly connected together as well as the actuating cam member 60 and the detaining cam.member 61,'with the plate 62 used to interconnect the four .cam members in position (see Figs. 8 and 9). The actuating cam members 58 and 60 are identical in shape to the actuating cam member 9 of Fig. 2, with the actuating cam member 60 shown in Fig. 6. Also, the detaining cam members 59 and 61 are identical in shape with the detaining cam member 10 of Fig. 2, with the detaining cam member 61 shown in Fig. 6.

The actuating cam member 58 and the dc taining cam member 59 coact with a detent 63, a latch 64, a latching pawl 65, a safety dog 66, and a link 55 in a similar manner as set forth for the coacting operations of the actuating cam member 9 and the detaining cam member 10 as heretofore explained. Similarly a detent 67, a latch 68, a latching pawl 69 and a safety dog 70 are provided in the frame member 57 and are shown in Fig. 6. These various interrelated moving parts which are mounted upon their respective right and left hand frame members 56 and 57, are held into position by plates 71 and 72 which are secured by suitable screws 73. The frame members 56 and 57 are connected by the bolts 74: and 75.

It is thus seen that there is a complete locking mechanism on each side of the plate 62 which engages the lever L in a manner to govern its movement in accordance with the locked condition of each set'of locking devices. i

F rom Fig. 6 it will be noted that there are slots 62, 62 and 62 in the plate 62 for allowing movement of the various cam members although the pins 76 and 77 are used to mount the latches 64 and 68, also the latch ing pawls and 69 respectively.

It is thus seen that this type of mechanism is very adaptable for multiple indication latch mechanisms, making it possible to include two indication latch mechanisms, that is, a multiple unit, in the same space occupied by a single indication latch mechanism.

As both the single and double indication latch mechanism units are the same size and are interchangeable the same mounting means may be used for securing both forms in their proper position in respect to the lever L.

With referenceto Fig. 1 it is seen that the spring biased wedge shaped detent D secures the mechanism in position by clamping the plate 7 8 against the frame 88 of the interlocking machine and the frame members 7 and 8 of the indication latch mechanism IL. The spring 79 then pushes the wedge 80 in such a manner that there is a constant tension upon the indication latch mechanism. The bolt 81 passes through the center of the wedge 80, spring 79 and plate 78 so that movement upon a horizontal plane is prevented. The wedge 80 is slidably attached to the plate 78 )by rivets 83 and 82v (see Figs. 10, 11 and 12 The advantage of such a spring biased Wedgemounting means is, thateach indication latch mechanism is tensioned with a uniform force so that the frame of the interlocking machine is not distorted from its proper position. It is noted, that should the wedge member-- be secured in position by tightening the bolt: 81, that there is no defi'' nite limit to determine when a proper tensioningforce is applied. Hence, there would be a varying stress throughout the length of the interlocking machine. n

Thus, an indication latch'mechanism has been shown and described, which is complete in a unit structure and may be easily placed in a. coacting position with its control lever. Also, means has been provided for mountingthe mechanism in such a manner that all mechanisms-have a uniform supporting, tension 'upon'them. V The present disclosure has further provided a type of locking means which directlytransmits all forces, which may be applied to the control lever, directly to the frames oftheindication latch mechanism, thus removingthe stresses which have heretofore been applied to the pivot points of such mechanisms. Also, this type of flocking-means readily adapts itself to mulcontrol; lever-,and a detachable unit indication latch mechanism including, a detent means capable of preventing the final movement of'said control lever to its extreme positions, actuating means rendering said detent means active, latching means locking said detent means in an active condition,'and means rendered active bythe application of electrical energy. to unlock said latching 'means. a

i 2. In an interlocking machine, a control lever, a guidingsupport member for said control lever, anda detachable unit indication latch mechanism including, two reciprocating cam membersoperated by said control lever, a-detent capable of preventing final movement of said cam members, means moving said detent to an active position before completionof movement of saidc ontrol lever to a new operating: position, lockingmeans caused to lock-said detent in an active positionzby completion of movementof said con trol lever to a new operating position, and means rendered active by application of elec-; trical energy to unlock said locking means.

3. In an interlockingmachine, a control lever, a guiding support member for said control lever, and a detachable unit indica; tion latch mechanismincluding, a detaining cam member actively engaging said control lever, an actuating cam member actively engaging said control lever, a detent capable of actively preventing final movement. I of said detaining cam member, a safety dog capable I of actively preventing final movementof said detaining cam member, a latching lever actively engaging, said detent, a locking pawl locking said detent in an active .positioniby locking said-latching lever eachtime said detent assumes an "active position, a releasing link being. capable of actuating said looking pawl and said safety dog for moving said detentandsaid safety dog to inactive positions,and'also being capable of preventing inter-mediate movement of said control i lever when n an actuating position by actively engaging said detaining camvmember.

4:. In an interlocking machine for railroads, a control lever, and an indication latch mechanism for preventing fin al movementof said control leveruntil after actuation of said mechanism, and for preventing intermediate movement during actuation of said mechanismiwith said indicationlatch mechanism including, a detainingcam member, an

actuating cam member, a slidably operable detent, a slidably operable safety dog, a latching lever, 21 locking-pawl biasedtoa locking position, a releasing link, andmeans op- .erably retaining saidsa-fety dog in a released position in opposition to said biased locking .pawluntil said safety dog is actuated by said actuating'cam memben;

5. In an interlocking machine for railroads, a control lever, locking means preventing final movement of saldicontrol lever including,a detaining cam member, an actuating cam.member,. a slidablyoperable detent, a slidably operable safety dog, a latching lever, alocking pawl, releasing means ,includlng an electro responsive devlce, areleasinglink, and said safety dog, and means ,preventingintermediate movement of said control lever during actuation of said releasing means including said detaining cam mem-' her and said releasing link.

6.'In an interlocking machine, a control 5 lever, a guiding support member for said control lever, and a detachable unit indication latch mechanism including, a safety dog capable of preventing final movement of said control lever, actuating means rendering said safety dog active, means rendered active by the application of electrical energy for controlling said safety dog to an inactive posi- 1! tion with said means including, an electro responsive device, and a releasing link, means preventing intermediate movement of said control lever during actuation of said safety dog to an inactive position including said releasing link, and means operably retaining said safety dog in an inactive position until acted upon by said actuating means.

7. In an interlocking machine, a control lever, a guiding support member for said control lever, a detachable unit indication latch mechanism, and means including a spring biased wedged member for mounting said indication latch mechanism in a coacting position relative to said control lever.

8. In an interlocking machine, a control lever, a guiding support member for said control lever, a detachable indication latch mechanism, and means including a wedge member, a coil spring for biasing said wedge member, a limiting plate, and a bolt attached to said guiding support member upon which said limiting plate is secured by a nut, and upon which said wedge member is slidably mounted, whereby said indication latch mechanism is mounted in a co'acting position relative to said control lever.

9. In a detachable unit indication latch mechanism for interlocking machines, a two part casing, an actuating cam member slidably mounted within said two part casing, means for actively connecting said actuating cam member with a control lever of an interlocking machine, a detaining cam member rigidly connected to said actuating cam member, an electro-responsive device, locking means preventing movement of said control lever to an extreme position except when actuated by said electro-responsive device,-locking means preventing movement of said control lever from one intermediate position to another intermediate position when said electro-responsive device is in an actuating condition.

10. In an interlocking machine, a control lever, a guiding support member for said control lever, a detachable indication latch mechanism including, a two part casing, a plurality of actuating cams and a plurality of detaining cams actively connected to said control lever, a plurality of detents and a plurality of safety dogs for preventing the final movement of said control lever, means locking said detents in active positions each time said detents are operated to active positions by their respective actuating cams, a plurality of electro magnets, means releasing a particular detent and a particular safety dog upon energization of a particular electro magnet, and means preventing movement of said control lever bet-ween intermediate positions while any one of said electro magnets is energized, whereby said control lever is prevented from completing its final movement until all of said electro magnets have been momentarily energized.

11. In an interlocking machine, a control lever, a guiding support member for said control lever, and a detachable unit indication latch mechanism including, a plurality of detent means each being capable of preventing the final movement of said control lever to its extreme positions, actuating means rendering said plurality of detent means active, a plurality of latching means locking their respective one of said detent means in an active condition, and a plurality of means rendered active by the application of electrical energy to unlock their respective latching means, whereby said control lever is prevented from movement to its extreme positions until after all of said detent means are controlled to active conditions.

12. In an interlocking machine, a control lever, a guiding support member for said control lever, and a detachable unit indication latch mechanism including, a plurality of reciprocating cam members operated by said control lever, a plurality of detents each capable of preventing final movement of said cam members, means moving each of said detents to active positions before completion of movement of said control lever to a new operating position, a plurality of locking means each caused to lock its respective one of said detents in an active position by completion of movement of said control lever to a new operating position, and a plurality of means each being rendered active by application of electrical energy to unlock its respective one of said locking means, whereby said control lever is prevented from being operated to extreme positions until all of said locking means have been unlocked.

18. In an interlocking machine, a control lever, a guiding support for said control lever, and a detachable unit indication latch mechanism including, a plurality of detaining cam members actively engaging said control lever, a plurality of actuating cam members actively engaging said control lever, a plurality of detents capable of actively preventing final movement of their respective one of said detaining cam members, a plurality of safety dogs being capable of actively preventing final movement of their respective one of said detaining cam members, a plurality of latching levers actively engaging their respective one of said detents, a plurality of locking pawls each one locking its respective one of said detents in an active position by locking its respective one of said latching levers each time its respective one of saidv detents assumes an active position, a plurality of releasing links each being capable of jointly actuating one of said locking pawls and one of said safety dogs respectively for controlling said safety dog and its respective one of said detents to inactive positions, and also being capable of preventing intermediate movement of said control lever when in an actuating position by actively engaging said detaining cam members, whereby said control lever is prevented from movement to either extreme position from the corresponding intermediate position until all of said detents and all of said safety dogs have been actuated to inactive positions, and whereby said control lever is prevented from being moved from one intermediate position to an other intermediate position during actuation of any one releasing link.

14. In an interlocking machine, in combination, a control lever, a guiding support member for said control lever, a unit indication latch mechanism member'for the control lever, and means detachably mounting the latch member in relation to the control lever.

15. In an interlocking machine, in combination, a control lever, a guiding support member for said control lever, a unit indication latch mechanism member for the con trol lever, and elastic tensioning means detachably mounting the latch member in relation to the control lever.

In testimony whereof I affix my si ature.

WINTHROP K. H WE. 

